Treating Opioid Dependency and Coexistent Chronic Nonmalignant Pain

As pointed out by Jackman and colleagues in this issue of American Family Physician, opioids are commonly used for the treatment of chronic nonmalignant pain (i.e., pain unrelated to cancer that persists beyond the usual course of disease or injury).1 Although most patients with chronic nonmalignant pain may be successfully treated with long-term opioids, there is a risk of drug misuse, abuse, and addiction.

One of the most common pain conditions seen in primary care is chronic low back pain. In one systematic review, 5 to 24 percent of patients who were prescribed long-term opioids had aberrant drug-taking behavior. The review authors noted that, although clinical trials suggest that opioids are effective for the short-term (less than 16 weeks), the effectiveness of long-term opioids (16 weeks or more) for pain relief and improved physical function is less clear.2

Less is known about the use of long-term opioids for other common chronic pain conditions. Recommendations are based on expert opinion and uncontrolled studies; however, several adverse effects are known to be associated with prolonged treatment with opioids. One study showed that the unintended consequences include accident proneness, impaired judgment and cognitive function, a decline in occupational and social function, and strained family relationships.3

Physicians should monitor patients for adverse effects.4 The patient's medical history may provide important clues. For example, if the patient is taking unusually large quantities of opioids and still complains of insufficient pain relief, there may be aberrant drug-taking behavior or drug diversion. This should not be confused with pseudoaddiction, in which patients appear to have drug-seeking behavior that is actually caused by inadequate pain control.

Some physicians may monitor patient response to long-term opioids with standardized questionnaires, such as the West Haven-Yale Multidimensional Pain Inventory, which measures the functionality of patients with chronic pain.5 Family members of the patient may also provide important information about possible misuse of prescription drugs; whereas at other times, they too have a substance abuse disorder. Physical signs (e.g., slurred speech, small pupils, unusual affect) could suggest aberrant drug-taking behaviors. The results of urine drug screening can also be valuable. These screens should be positive for prescribed medications, negative for medications that have not been prescribed, and negative for illicit drugs. When prescription drug abuse is suspected or found, Jackman and colleagues suggest that these patients could be referred to a pain management specialist for counseling or treatment.1

The current standard of care used by pain management specialists to treat patients with chronic pain and aberrant drug-taking behavior is an abstinence-oriented approach. In this approach, patients initially discontinue their opioid use for a “drug holiday.” Formal inpatient or outpatient detoxification is sometimes required to stabilize opioid withdrawal syndrome. Following this, patients are given multidisciplinary treatment for opioid dependency and chronic pain, including cognitive behavior therapy (i.e., for chronic pain and a substance abuse disorder) that is concurrent with nonopioid pain management.6

Effective alternatives to abstinence-oriented treatment include maintenance-oriented approaches using methadone7 or buprenorphine (Subutex).8,9 Although methadone has been demonstrated to be effective as an analgesic and for maintenance-oriented treatment of opioid dependence, it has adverse effects common to all opioids (e.g., constipation) and serious adverse events related to its long half-life (e.g., drug overdose, death) that limit its effectiveness.10 Buprenorphine is a partial muopioid agonist with a low risk of overdose that has been used as an alternative to methadone for maintenance-oriented treatment, and like full muopioid agonists, it has analgesic properties.8,9 For outpatient use, buprenorphine is combined with naloxone (Suboxone) and can be useful for the treatment of patients with opioid dependence and co-occurring chronic pain because of its effectiveness in providing analgesia and treating opioid dependency, and its low abuse liability.11

A combined approach, using cognitive behavior approaches and maintenance-oriented buprenorphine/naloxone pharmacotherapy may be effective in treating patients with opioid dependence and co-occurring chronic pain. Unfortunately, there have only been uncontrolled studies investigating these combined approaches. Randomized controlled trials need to be completed in order to provide more informed clinical guidelines.